ZenithDefy Inventor

Paul O'Neil

Zenith’s appropriately-named “Defy” collection is all about defying conventions. In its relatively short history it has spawned the world’s first chronograph that could measure elapsed time to 100th of a second (Defy El Primero 21) and a rethink of the gyroscopic tourbillon (Defy Zero G). Two years ago, the collection incorporated the biggest revolution in mechanical watchmaking since the invention of the pendulum, when the Defy LAB introduced an entirely new form of oscillator.

Over the intervening two years, Zenith has refined its oscillator to take it from a prototype that was seen in only 10 watches to a production version that is now presented in several hundred watches in the new Defy Inventor. As a reminder, the Zenith oscillator is made (or, to put it more accurately, “grown”) from a single piece of silicon that is produced to the exact requirements determined by the equations developed by Guy Semon and his team at the LVMH Lab. This “monolithic” oscillator uses the principles of compliant mechanics to replace all 30 parts of the traditional regulating organ, since flexible elements and levers incorporated directly into the monolithic silicon structure mean that it can act as both oscillator and lever.

The original Zenith oscillator in the Defy Lab vibrated at a frequency of 15 Hz, but the new production variant increases this to 18 Hz (129,600 vibrations per hour) for a tiny amplitude that is just several degrees (compared to the 300 degrees of amplitude required for a normal balance-spring assembly). The combination of a high frequency and a low amplitude offer exceptional performance over the entire power reserve of 50 hours without any need for lubrication. As a result, the new calibre ZO 9100 is chronometer certified by TimeLab.

Because the monolithic oscillator is just 0.5mm thick and replaces a regulating organ that usually occupies a thickness of up to 5mm, the weight saving in the Defy Inventor’s movement means that it can operate for 50 hours despite running at a frequency that is over three times that of a conventional mechanical watch. The ultra-lightweight philosophy has also been carried over to the 44mm case, which is made in titanium with an Aeronith bezel. Aeronith was also developed in-house within the LVMH watchmaking division and is 2.7 times lighter than titanium, 1.7 times lighter than aluminium and even 10% lighter than carbon. It is produced by heating aluminium until it becomes an open-pore metal foam. A lightweight polymer is then injected into the interstices to create an extremely lightweight material. It also has an appealing stippled texture.

Although everything about the Defy Inventor is brimming with cutting-edge technology, the time display itself is as traditional as it gets, with central hour, minute and seconds hands red against facetted hour markers. Apart from the Zenith logo at 12 o’clock, nothing is allowed to spoil the mesmerizing jitter of the high-frequency oscillator – not even a date window.